The Construction Technology And Deformation Settlement, Using Vacuum And Stack Combined Preloading To Consolidate

Based on the project of Fenghua three highs connecting, regarding the earth’s surface environment complex, soft soil ground, the great and tight project, abundant underground water and rainfall etc., This Article deeply analyzed the reinforcement mechanism of vacuum preloading, surcharge preloading and vacuum combined stack surcharge loading.Based on the vacuum combined surcharge preloading processing of highway soft foundation, its construction process technology is particularly important. Mainly includes three aspects: the construction process technology of plastic drainage plate, vacuum preloading construction technology and construction technology of stack preloading. During construction process of plastic drainage plate, four aspects needs to be watched: Jack is unfavorable to be shrinkage cavity; promoting guide pipe with belt on; drainage plate to be polluted or damaged; the inserting speed of the plate needs to be careful considering the earth situation.Analysis of the vacuum preloading method and surcharge preloading reinforcement mechanism, from the reinforcement mechanism, three aspects of stress path and intensity contrast analyzed the characteristics of the two methods. Combined with vacuum preloading method and stack surcharge preloading, explained the vacuum combined stack surcharge preloading construction process technology. And consolidation of the vacuum preloading method and stack surcharge preloadingcould be superposed, which final effect is equivalent to the vacuum combined surcharge preloading. From consolidation pressure, the lateral extrusion deformation and inward contraction deformation offset each other, the effect of plastic drainage plate three aspects discussed effect of superposition on the soil.Starting from the construction of vacuum combined surcharge preloading, according to the analysis of the field construction progress on site and the tight time, here analyzes the causes of prophase vacuum degree increase rate slowly in the process of construction. Firstly, poor airtightness is affecting vacuum degree increase rate in the main cause, then reconfirm the vacuum preloading of terminal factor, and then to improve the concrete construction method, to speed up the construction progress.Explained the settlement deformation of vacuum combined surcharge preloading theory forecasting method, that is the engineering commonly used stratified summation method, conducted calculation methods of horizontal consolidation, vertical consolidation and total consolidation. Using the method of theory combining with Fenghua high connecting engineering actual situation, the change of the total consolidation in the construction process have been calculated and the final settlement & deformation, which is compared with the real measured settlement of the scene of vacuum combined surcharge preloading method, and compared with the theoretical final deformation.